Pony.fm/app/Http/Controllers/ImagesController.php

<?php

namespace App\Http\Controllers;

use App\Image;
use Config;
use Illuminate\Support\Facades\App;
use Illuminate\Support\Facades\Redirect;
use Response;
use URL;

class ImagesController extends Controller
{
    public function getImage($id, $type)
    {
        $coverType = Image::getImageTypeFromName($type);

        if ($coverType == null) {
            App::abort(404);
        }

        $image = Image::find($id);
        if (!$image) {
            App::abort(404);
        }

        $response = Response::make('', 200);
        $filename = $image->getFile($coverType['id']);

        if (!is_file($filename)) {
            $redirect = URL::to('/images/icons/profile_' . Image::$ImageTypes[$coverType['id']]['name'] . '.png');

            return Redirect::to($redirect);
        }

        if (Config::get('app.sendfile')) {
            $response->header('X-Sendfile', $filename);
        } else {
            $response->header('X-Accel-Redirect', $filename);
        }

        $response->header('Content-Disposition', 'filename="' . $filename . '"');
        $response->header('Content-Type', 'image/png');

        $lastModified = filemtime($filename);

        $response->header('Last-Modified', $lastModified);
        $response->header('Cache-Control', 'max-age=' . (60 * 60 * 24 * 7));

        return $response;
    }
}